LONDON (Reuters Breakingviews) - WAREHOUSE HAVEN. Masayoshi Son is reverting to his preferred investment theme: robots. The SoftBank Group chief executive’s company on Monday said it had agreed to pay $2.8 billion for a 40% stake in AutoStore, a Norwegian company which makes robotics for warehouses. The deal values the 25-year-old group at $7.7 billion including debt. Demand from customers like Siemens and Puma for AutoStore’s automated warehouses has benefited from bumper online sales. The company’s last reported results for 2019 showed adjusted EBITDA of $108 million, implying a multiple of 71 times. But then UK rival Ocado, whose enterprise value is 15 billion pounds, generated EBITDA of just 43 million pounds in 2019. The two companies are engaged in a long-running legal battle over patents. Research group Statista estimates that the global warehouse automation market will double to $30 billion by 2026, from $15 billion in 2019. The robot rivals have much to fight over. (By Karen Kwok)